Air lift pumps are well-known devices for raising a liquid from a depth, and are advantageous in many circumstances over conventional, positive pressure pumps. One advantage is cost effectiveness, due to extreme simplicity in design. Another advantage is improved reliability air lift pumps have few or no moving parts to wear out, and are particularly well suited for moving brine or other corrosive liquids.
Air lift pumps are not, however, always suitable for a given task. Known air lift pumps may, for example, be inefficient or inadequate to move large volumes of liquid. Air lift pumps may also be problematic in that the compression equipment need to provide the compressed gas is generally located above-ground, which may create undesirable noise.
Thus, there is a continued need for methods and apparatus which improve the utility of air lift pumps.